A review on feedback current control techniques of grid-connected PV inverter system with LCL filter

This paper presents the different feedback current control techniques of the grid connected inverter systems with LCL filter. In this work, different possible feedback current control techniques for a grid connected inverter and their performance have been discussed. The performance study is carried out from different perspectives such as rejection of disturbance in grid voltage and the stability condition when the PV system undergoes different surrounding conditions. Classic PI controllers have been used in all case of control strategies and the inverter is operated in current control mode. In order to minimize the switching losses, an LCL filter is used between the PV inverter and grid. There are four possible control strategies are discussed here and the prime focus in this paper is on the design of each control method and find out the most suitable control method by making a brief comparative analysis among them. The current control methods are then applied to 1-KVA, 110V, 50Hz single-phase grid-connected inverter system. The inverter output impedance is considered here for their performance evaluation.